An adhesive tape of the kind mentioned above is known from DE 103 12 031 A1. This document describes a decidedly flame retardant pressure-sensitive adhesive compound comprising at least one acrylate adhesive component, at least one ammonium polyphosphate component, and at least one resin component. The known pressure-sensitive adhesive compound is preferably composed of at least 35% by weight of acrylate adhesive component, at least 25% by weight of ammonium polyphosphate, in particular 30 to 40% by weight, and also at least 25% by weight of resin component. The presence of the ammonium polyphosphate component is primarily responsible for the inhibition of the flammability of the pressure-sensitive adhesive compound known from DE 103 12 031 A1.
The production of double-sided adhesive tapes is also described in DE 103 12 031 A1, wherein the application in the hot-melt method was carried out exclusively on textiles, substrates made from plastic fibers, such as on nonwoven fabrics, in particular PET nonwoven fabrics, woven fabrics or so-called nonwoven geotextiles. A multitude of suitable composites are described for the acrylate adhesive component, wherein this component can be preferably produced by copolymerization of different co-monomers. In a preferred embodiment of the pressure-sensitive adhesive compound, it is provided that at least one co-monomer is a photoinitiator with a copolymerizable double bond. Photoreactive groups incorporated by polymerization facilitate the possibility of a reaction of the chain with neighboring chains upon exposure to ultraviolet radiation, so that a crosslinking structure is created such as those that are typical for adhesives, in particular for pressure-sensitive adhesives with UV-crosslinkable acrylate as main component.
One key parameter for an adhesive tape is its adhesive force, which may require different magnitudes according to the particular application. Standard methods are frequently used to determine this parameter, such as, for example, the determination of the adhesive force on steel according to DIN EN 1939 (status 2003). The adhesive force on steel was also determined according to DE 103 12 031 A1, but according to a non-standardized special method, which is described in the mentioned document. The adhesive force on steel determined in this way was within the range of 8.0 N/cm to 8.7 N/cm for various embodiments described as examples. These values were assessed in the document as being an improvement of the adhesive force with respect to conventional adhesive compounds.
Under “moderate adhesive force” is understood according to DIN EN 1939 an adhesive force within the range of 0.5 N/cm to 4.0 N/cm; under “increased adhesive force” is understood according to DIN EN 1939 an adhesive force within the range of 4.0 N/cm to 10.0 N/cm. A differentiated adhesive force such as this plays an important role in particular when dealing with the bonding of nonpolar surfaces.
Another key parameter for an adhesive tape is its shear strength. High values are required for the shear strength, in particular where an adhesive tape is designed as a double-sided adhesive tape intended for bonding together different components, wherein standard methods are likewise often used to determine said values, such as, for example, the determination of shear strength according to DIN EN 1943 (status 2002).
Under “moderate shear strength” is understood according to the application a shear strength within the range of 100 minutes to 1,000 minutes according to DIN EN 1943. Under “increased shear strength” is understood a shear strength within the range of 1,000 minutes to 10,000 minutes according to DIN EN 1943. Under “very high shear strength range” are understood values greater than 10,000 minutes, wherein the exact end of the measurement as a rule cannot be ascertained.